Datasheet

20
7593L–AVR–09/12
AT90USB64/128
6. Atmel AVR AT90USB64/128 memories
This section describes the different memories in the AT90USB64/128. The AVR architecture has
two main memory spaces, the Data Memory and the Program Memory space. In addition, the
AT90USB64/128 features an EEPROM Memory for data storage. All three memory spaces are
linear and regular.
Notes: 1. Byte address.
2. Word (16-bit) address.
6.1 In-system re-programmable flash program memory
The AT90USB64/128 contains 128Kbytes On-chip In-System Re-programmable Flash memory
for program storage. Since all AVR instructions are 16 or 32 bits wide, the Flash is organized as
64K × 16. For software security, the Flash Program memory space is divided into two sections,
Boot Program section and Application Program section.
The Flash memory has an endurance of at least 100,000 write/erase cycles. The
AT90USB64/128 Program Counter (PC) is 16 bits wide, thus addressing the 128K program
memory locations. The operation of Boot Program section and associated Boot Lock bits for
Table 6-1. Memory mapping.
Memory Mnemonic AT90USB64 AT90USB128
Flash
Size
Flash size 64Kbytes 128K bytes
Start address
- 0x00000
End address
Flash end
0x0FFFF
(1)
0x7FFF
(2)
0x1FFFF
(1)
0xFFFF
(2)
32 registers
Size
- 32bytes
Start address
- 0x0000
End address
- 0x001F
I/O registers
Size
- 64 bytes
Start address
- 0x0020
End address
- 0x005F
Ext I/O
registers
Size
- 160bytes
Start address
- 0x0060
End address
- 0x00FF
Internal
SRAM
Size
ISRAM size 4Kbytes 8Kbytes
Start address
ISRAM start 0x0100
End address
ISRAM end 0x10FF 0x20FF
External
Memory
Size
XMem size 0-64Kbytes
Start address
XMem start 0x1100 0x2100
End address
XMem end 0xFFFF
EEPROM
Size
E2 size 2Kbytes 4Kbytes
Start address
- 0x0000
End address
E2 end 0x07FF 0x0FFF